Injector heater



July 9, 1940. i J c wHlTE v 2,207,390

INJECTOR HEATER Filed y 51, 1959 Q4 R n N N I N ENTOR. Jfzzz 0. law

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Patented July 9, 1940 PATENT oFr-icc INJECTOR, HEATER John C. White,Madison, Wis" I I Ap l cation July 31, 1939, SerialNo. 287,450

2 Claims. Thisiinventionirelates to apparatus for heating fluids bymeans of steam, either live or exhaust,

and constitutes an improvement upon the heater disclosed in my PatentNo. 2,066,867, issued January 5, 1937. 9

With the use of a heater such as disclosed in said patent,'thetemperature of the fluid beingsteam to waterflow in the injector propermust be such as to maintain a vacuum of about 20 inches mercury at thethroat of the venturi or combining tube, and any attempt to attain afinal temperature above 165 F. by increasing the 'steamrelatively to theamount of water introduced will so reduce the vacuumat the throat of theventuri as to cause unstable and unsatisfactory operation.

The primary purpose of my present invention is to provide an injectorheater by which the liquid being heated may be raised to a temperatureconsiderably above the maximum of 165 F. heretofore attainable. In fact,my present invention is capable of delivering the efliuent at atemperature higher than 200 F., and in actual tests an effluenttemperature of 210 F. has been attained. For certain purposes, such asmilk drying and other processes, such high temperatures are verydesirable, and the requirements of such methods may be met by employingan injector heater constructed in accordance with the principles of mypresent invention.-

While my invention is capable of many uses, it is here shown forillustrative purposes as incorporated in a heat exchange system of thegeneral type exemplified in my prior Patent No. 2,158,809, issued May16, 1939.

Referring to the accompanying drawing,

Fig. 1 is a perspective view of a heat exchange system embodying myimproved injector heater;

Fig. 2 is a longitudinal sectional View of a heater constructed inaccordance with my invention; and

Fig. 3 is a transverse sectional view on the line 33 of Fig. 2.

The system chosen for the purposes of exemplifying the principles of myinvention and illustrated in Fig. 1 is similar to that disclosed in myprior Patent No. 2,158,809, and comprises a heat exchanger 4 of thedouble pipe type in which the outer pipes conduct the heating fluidaround the inner pipes containing the fluid to be heated. A storage tank5 supplies a constant head of water for the injector heater 6 to whichthe water from the tank is conducted by a pipe 1 and from which theheated water is conducted to the lowermost coil of the heat exchanger bya pipe 8.

Asteam supply line 9 carrying either live or 5 exhaust steam is providedwith a thermostatie cally controlled valve H for regulating the flow ofsteam through the pipe I2 to the heater which heats and simultaneouslypropels the water through pipe 8 to the coils. The water emerges fromthe coils into a pipe 13 by which it is returned to the storage tank.The tank is equipped with an overflow pipe l4 and a supply pipe 15equipped with a float controlled valve I 6. k The fluid to be heated issupplied to the heat exchanger throughpipe l1, and the flow'of heatingfluid to the exchanger is controlled through a diaphragm actuated valve18 by the flow of fluid through pipe l1. Further details of theapparatus need not be described here, as they are fully disclosed insaid Patent No. 2,158,809.

- The injector heater 6, by which the'water delivered from the tank 5through the pipe I is heated by the steam delivered to the heater fromthe pipe I2, comprises as shown in Fig. 2 a combining tube l9 and adelivery tube 2| having their opposed ends maintained in spaced relationby a cylindrical sleeve 22 which provides an overflow chamber from whichthe overflow is delivered through a pipe 23. The steam entering frompipe I2 is delivered into the intake end of the combining tube l9through a nozzle 24 projecting through a chamber 25 to which the wateris supplied by the pipe 1. The water is drawn by the injector action ofthe delivered steam into the combining tube, with the result that thesteam and water are combined during their travel therethrough, the waterbeing heated by absorbing the heat units of the steam and the steambeing at the same time condensed. The combined flow of heated water isdischarged at high velocity across the gap between tubes l9 and 2| inoverflow chamber 22. Entering the delivery tube 2|, its velocity head isgradually converted to pressure head and it emerges through pipe 8 tothe point of use.

The construction of the heater thus far described is similar to thatdisclosed in my Patent No. 2,066,867, but as previously stated, it isimpossible with thisheater to attain a delivery temperature of theefiluent in excess of approximately 165 F. For the purpose of increasingthe delivery temperature of the efiluentwithout detracting from theeflici-ency of the heater, my present invention contemplates furtherheating the eflluent by delivering steam thereto in the supply pipe 9.The steam thus supplied is drawn into the delivery tube and furtherheats the liquid flowing therethrough so that the temperature of thedelivered efiiuent is raised from a previous maximum of F. to atemperature above 200 F. and closely approaching the boiling point ofThe steam supply pipes 9 and 29 are equipped with hand operable shut-offvalves 3! and 32, respectively. In starting the operation, valve 32 isclosed, and valve 3! is opened to admit steam .to the heater inproportions determined by the temperature controlling valve ll so as todeliver the heated, fluid to pipe 8 from the heater at a temperature notover 165 F., which is the maximum temperature at which an injectorheater could normally be operated prior to my invention.

Inorder to obtain a higher temperature, the valve 32 is gradually openedadmitting supplementary steam to the delivery tube through the annularpassage 2! until the desired final temperature is attained. When set forthe desired temperature, the system will continue to operateautomatically without further attention.

The structural details of the heater may of course be varied. withinconsiderable limits without departing from the scope of the invention asdefined in the following claims.

I claim:

1. An injector heater having a Venturi passage comprising a taperedcombining tube forming an intake at its larger end and a tapereddelivery tube forming an expanding portion for the passage, the saidexpanding portion having an area of low pressure during operation of theinjector, said tubes being arranged in alignment with their smaller endsadjacent to each other, an overflow chamber surrounding the adjacentends of said tubes, means for supplying to the intake end of saidcombining tube the liquid to be heated and steam for heating the same,and means for introducing additional steam into the low pressure area ofthe expanding portion of the passage close to the overflow chamber.

2. An injector heater having a Venturi passage comprising a taperedcombining tube forming an intake at its larger end and a tapereddelivery tube forming an expanding portion for the passage, the saidexpanding portion having an area of low pressure during operation of theinjector, said tubes being arranged in alignment with their smaller endsadjacent to eachother, an overflow chamber surrounding the adjacent endsof said tubes, means for supplying to the intake end of said combiningtube the liquid to be heated and steam for heating the same, an annularchamber surrounding the bore of the expanding portion of said passageclose to the overflow chamber and communicating with the low pressurearea of the passage, and a steam supply connected with said annularchamber for introducing additional steam into the passage.

JOHN C. WHITE.

